It is a little difficult and long to explain, however, I try to give you an exhaustive response.
The Tattoo on Chrollos forehead is the Sun Cross because Chrollo represents the Sun and the 12 members of Genei Ryodan are the 12 Months (For example Uvo-November in the prophecy, 11 the number of the spider tattoo). Ther 12 months revolution of Earth around the Sun in a Year
Chrollo-Jesus (The sun) and the 12 members of the Ryodan (12 apostles/12 months/12 Zodiac signs, as said in the prophecy).
There is a symbolic meaning in relation to these characters:
- Gensuru and Sub and Bara vs Tsezugera
- Chrollo and Genei Ryodan Members vs Hisoka
The color of characters' hair represent the duality: Yang/White hair and Yin/Black Hair
Chrollo and Tsezugera=Black Hair (Yin) and similar hairstyle
Hisoka and Genthru=White hair (Yang) and a similar hairstyle (with Hisoka and Genthru both psychopaths and enemies of Gon)
1) Hisoka vs Chrollo
2) Genthru vs Tsezugera
Similarities:
Chrollo has a Black trenchcoat with a Reversed Cross
Genthru have a White trenchcoat with a Normal Cross
They are similar but reversed:
Part 1:
-Chrollo with the Sun Cross on his forehead
-Hisoka with the Star and Tear Tattoos (Mask of Comedy and Mask of Tragedy)
Part 2:
-Chrollo and Hisoka have both tattoos but Genei Ryodan members don't have tattoos
-Genthru and Tsezugera don't have tattoos but Sub and Bara have tattoos
Genthru with Sub and Bara (Criminals/Thieves) is similar to Hisoka (or Chrollo) with Genei Ryodan members (Criminals/Thieves)
Sub (White hair/Yang) and Bara (Black hair/Yin) Tattoos are like Sun and Moon (of Chrollo), Yang and Yin.
Chrollo-Jesus (The sun) and the 12 members of the Ryodan (12 apostles/12 months/12 Zodiac signs, as said in the prophecy).
2) Genthru vs Tsezugera
Similarities:
Chrollo has a Black trenchcoat with a Reversed Cross
Genthru with Sub and Bara (Criminals/Thieves) is similar to Hisoka (or Chrollo) with Genei Ryodan members (Criminals/Thieves)
